| /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ |
| #ifndef _ASMX86_DEBUGREG_H_ |
| #define _ASMX86_DEBUGREG_H_ |
| |
| |
| /* Indicate the register numbers for a number of the specific |
| debug registers. Registers 0-3 contain the addresses we wish to trap on */ |
| #define DR_FIRSTADDR 0 /* u_debugreg[DR_FIRSTADDR] */ |
| #define DR_LASTADDR 3 /* u_debugreg[DR_LASTADDR] */ |
| |
| #define DR_STATUS 6 /* u_debugreg[DR_STATUS] */ |
| #define DR_CONTROL 7 /* u_debugreg[DR_CONTROL] */ |
| |
| /* Define a few things for the status register. We can use this to determine |
| which debugging register was responsible for the trap. The other bits |
| are either reserved or not of interest to us. */ |
| |
| /* Define reserved bits in DR6 which are always set to 1 */ |
| #define DR6_RESERVED (0xFFFF0FF0) |
| |
| #define DR_TRAP0 (0x1) /* db0 */ |
| #define DR_TRAP1 (0x2) /* db1 */ |
| #define DR_TRAP2 (0x4) /* db2 */ |
| #define DR_TRAP3 (0x8) /* db3 */ |
| #define DR_TRAP_BITS (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3) |
| |
| #define DR_STEP (0x4000) /* single-step */ |
| #define DR_SWITCH (0x8000) /* task switch */ |
| |
| /* Now define a bunch of things for manipulating the control register. |
| The top two bytes of the control register consist of 4 fields of 4 |
| bits - each field corresponds to one of the four debug registers, |
| and indicates what types of access we trap on, and how large the data |
| field is that we are looking at */ |
| |
| #define DR_CONTROL_SHIFT 16 /* Skip this many bits in ctl register */ |
| #define DR_CONTROL_SIZE 4 /* 4 control bits per register */ |
| |
| #define DR_RW_EXECUTE (0x0) /* Settings for the access types to trap on */ |
| #define DR_RW_WRITE (0x1) |
| #define DR_RW_READ (0x3) |
| |
| #define DR_LEN_1 (0x0) /* Settings for data length to trap on */ |
| #define DR_LEN_2 (0x4) |
| #define DR_LEN_4 (0xC) |
| #define DR_LEN_8 (0x8) |
| |
| /* The low byte to the control register determine which registers are |
| enabled. There are 4 fields of two bits. One bit is "local", meaning |
| that the processor will reset the bit after a task switch and the other |
| is global meaning that we have to explicitly reset the bit. With linux, |
| you can use either one, since we explicitly zero the register when we enter |
| kernel mode. */ |
| |
| #define DR_LOCAL_ENABLE_SHIFT 0 /* Extra shift to the local enable bit */ |
| #define DR_GLOBAL_ENABLE_SHIFT 1 /* Extra shift to the global enable bit */ |
| #define DR_LOCAL_ENABLE (0x1) /* Local enable for reg 0 */ |
| #define DR_GLOBAL_ENABLE (0x2) /* Global enable for reg 0 */ |
| #define DR_ENABLE_SIZE 2 /* 2 enable bits per register */ |
| |
| #define DR_LOCAL_ENABLE_MASK (0x55) /* Set local bits for all 4 regs */ |
| #define DR_GLOBAL_ENABLE_MASK (0xAA) /* Set global bits for all 4 regs */ |
| |
| /* The second byte to the control register has a few special things. |
| We can slow the instruction pipeline for instructions coming via the |
| gdt or the ldt if we want to. I am not sure why this is an advantage */ |
| |
| #ifdef __i386__ |
| #define DR_CONTROL_RESERVED (0xFC00) /* Reserved by Intel */ |
| #else |
| #define DR_CONTROL_RESERVED (0xFFFFFFFF0000FC00UL) /* Reserved */ |
| #endif |
| |
| #define DR_LOCAL_SLOWDOWN (0x100) /* Local slow the pipeline */ |
| #define DR_GLOBAL_SLOWDOWN (0x200) /* Global slow the pipeline */ |
| |
| /* |
| * HW breakpoint additions |
| */ |
| |
| #endif /* _ASMX86_DEBUGREG_H_ */ |